The movement I see is the trough acting like a mellonballer - scooping the convection off the western side. So now Ernesto is dealing with an adjacent trough, being over land, and interacting with mountains. I don't think it will be completely dissapated, but regeneration will start from a very weak depression instead of a strong tropical storm - and that will make a big difference if Ernesto does end up hitting Florida.
the only convection it's got now is that part over the windward passage...